Short circuit detection circuit

Abstract

This invention provides a short-circuit detection circuit, comprising a control circuit, a drive push-pull amplifier circuit, and a drive desaturation protection circuit. The input terminal of the drive push-pull amplifier circuit is connected to the output terminal of the control circuit, and the output terminal of the drive push-pull amplifier circuit is connected to the gate of the IGBT, used to control the IGBT to conduct according to the control signal of the control circuit. The drive desaturation protection circuit includes a blanking capacitor charging circuit and a fast disconnect circuit. The input terminal of the blanking capacitor charging circuit is connected to the collector of the IGBT, and the output terminal of the blanking capacitor charging circuit is connected to the input terminal of the fast disconnect circuit. The input terminal of the fast disconnect circuit is also connected to the output terminal of the control circuit and the input terminal of the drive push-pull amplifier circuit, respectively. This invention can achieve IGBT short-circuit protection through hardware circuitry, reducing cost and maintenance difficulty.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and more specifically to a short-circuit detection circuit. Background Technology

[0002] Insulated-gate bipolar transistors (IGBTs) are widely used in various fields, such as electric vehicles, rail transportation, industrial equipment, and home appliances. Therefore, ensuring the stability of IGBTs is particularly important. Currently, when an IGBT short-circuits, it needs to be shut down within a short time to prevent it from overheating and being damaged.

[0003] When an IGBT experiences a short circuit, desaturation occurs, meaning the IGBT exits the saturation region and enters the linear region. At this point, the voltage between the collector and emitter of the IGBT will rapidly increase from the saturation voltage drop to the bus voltage. Currently, to quickly turn off the IGBT when desaturation occurs, the protection function built into the driver chip detects the voltage between the collector and emitter and compares it with a reference voltage. A comparator within the driver chip performs this comparison, and a fault is detected when the collector-emitter voltage exceeds the reference voltage. However, ordinary driver chips do not have this function; a dedicated driver chip is required. Dedicated driver chips are more expensive and more difficult to repair. Summary of the Invention

[0004] This invention provides a short-circuit detection circuit, which aims to solve the problems of high cost and difficult maintenance caused by the current need to protect IGBTs with dedicated driver chips.

[0005] In a first aspect, the present invention provides a short-circuit detection circuit, comprising a control circuit, a drive push-pull amplifier circuit, and a drive desaturation protection circuit; the input terminal of the drive push-pull amplifier circuit is connected to the output terminal of the control circuit, and the output terminal of the drive push-pull amplifier circuit is connected to the gate of the IGBT, for controlling the IGBT to conduct according to the control signal of the control circuit; the drive desaturation protection circuit comprises a blanking capacitor charging circuit and a fast disconnect circuit, the input terminal of the blanking capacitor charging circuit is connected to the collector of the IGBT, the output terminal of the blanking capacitor charging circuit is connected to the input terminal of the fast disconnect circuit, and the input terminal of the fast disconnect circuit is also connected to the output terminal of the control circuit and the input terminal of the drive push-pull amplifier circuit respectively; wherein, when the IGBT fails, the output voltage of the blanking capacitor charging circuit reaches the conduction voltage of the fast disconnect circuit, and the fast disconnect circuit pulls down the input voltage of the input terminal of the drive push-pull amplifier circuit to quickly disconnect the IGBT.

[0006] Furthermore, it also includes a drive fault isolation circuit, the input terminal of which is connected to the output terminal of the blanking capacitor charging circuit, and the output terminal of which is connected to the input terminal of the control circuit; wherein, when the IGBT is working normally, the drive fault isolation circuit outputs a first signal to the control circuit to make the control circuit continuously output the control signal, and when the IGBT is short-circuited, the drive fault isolation circuit outputs a second signal to the control circuit to make the control circuit stop outputting the control signal.

[0007] Furthermore, the fast disconnect circuit includes a first transistor, a second transistor, and a third transistor; the base of the first transistor is connected to the output terminal of the control circuit, the collector of the first transistor and the base of the second transistor are both connected to the first power supply, the collector of the second transistor and the base of the third transistor are both connected to the output terminal of the blanking capacitor charging circuit, the collector of the third transistor is connected to the input terminal of the drive push-pull amplifier circuit, and the emitters of the first transistor, the second transistor, and the third transistor are all grounded.

[0008] Furthermore, the fast disconnect circuit also includes a first resistor, one end of which is connected to the first power supply, and the other end of which is connected to the collector of the first transistor and the base of the second transistor, respectively.

[0009] Furthermore, the drive push-pull amplifier circuit includes a fourth transistor and a fifth transistor; the base of the fourth transistor and the base of the fifth transistor are both connected to the output terminal of the control circuit, the collector of the fourth transistor is connected to the first power supply, the emitter of the fourth transistor and the emitter of the fifth transistor are both connected to the gate of the IGBT, and the collector of the fifth transistor is grounded.

[0010] Furthermore, the drive push-pull amplifier circuit also includes a second resistor, a third resistor, a fourth resistor, a first capacitor, and a first diode; one end of the second resistor is connected to the output terminal of the control circuit, the other end of the second resistor is connected to the base of the fourth transistor and the base of the fifth transistor respectively, one end of the third resistor is connected to the emitter of the fourth transistor, one end of the fourth resistor is connected to one end of the fifth transistor, the other ends of the third resistor, the other ends of the fourth resistor, and the anode of the first diode are all connected to the gate of the IGBT, the cathode of the first diode and one end of the first capacitor are both connected to the first power supply, and the other end of the first capacitor is grounded.

[0011] Furthermore, the blanking capacitor charging circuit includes a series circuit composed of multiple blanking resistors connected in series and a second capacitor; the input terminal of the series circuit is connected to the collector of the IGBT, the output terminal of the series circuit is connected to one end of the second capacitor, the input terminal of the drive fault isolation circuit and the input terminal of the fast disconnect circuit, and the other end of the second capacitor is grounded.

[0012] Furthermore, the blanking capacitor charging circuit also includes a second diode, the anode of which is connected to the output terminal of the series circuit, and the output terminal of which is connected to the first power supply.

[0013] Furthermore, the drive fault isolation circuit includes a third diode and an optocoupler; the negative terminal of the third diode is connected to the output terminal of the blanking capacitor charging circuit, the positive terminal of the third diode is connected to one end of the optocoupler, and the other end of the optocoupler is connected to the input terminal of the control circuit.

[0014] Furthermore, the drive fault isolation circuit also includes a fifth resistor and a sixth resistor; one end of the fifth resistor is connected to the second power supply, the other end of the fifth resistor is connected to one end of the sixth resistor, one end of the sixth resistor is also connected to the optocoupler, and the other end of the sixth resistor is connected to the input terminal of the control circuit.

[0015] The short-circuit detection circuit disclosed in this invention controls the IGBT to conduct when the IGBT is normal, through the control circuit driving the push-pull amplifier circuit. When a short circuit occurs in the IGBT, the output voltage of the blanking capacitor charging circuit increases, causing the fast disconnect circuit to conduct. The fast disconnect circuit pulls down the voltage at the input terminal of the drive push-pull amplifier circuit, causing the IGBT to disconnect quickly. With the above circuit, IGBT protection can be achieved solely through hardware circuitry without relying on a dedicated driver chip, reducing cost and maintenance difficulty. Attached Figure Description

[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a block diagram of a short-circuit detection circuit provided in an embodiment of the present invention;

[0018] Figure 2 This is a block diagram of a short-circuit detection circuit provided in another embodiment of the present invention;

[0019] Figure 3 This is a circuit diagram of a short-circuit detection circuit provided in an embodiment of the present invention;

[0020] Figure 4 This is a circuit diagram of a fast disconnect circuit for a short-circuit detection circuit provided in an embodiment of the present invention;

[0021] Figure 5 This is a circuit diagram of a drive push-pull amplifier circuit for a short-circuit detection circuit provided in an embodiment of the present invention;

[0022] Figure 6 This is a circuit diagram of the blanking capacitor charging circuit of a short-circuit detection circuit provided in an embodiment of the present invention; and

[0023] Figure 7 This is a circuit diagram of the drive fault isolation circuit of the short-circuit detection circuit provided in an embodiment of the present invention. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be understood that, when used in this specification and the appended claims, the terms “comprising” and “including” indicate the presence of the described features, integrals, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, operations, elements, components and / or collections thereof.

[0026] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used in this specification and the appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes such combinations.

[0027] Furthermore, the directional terms used in this invention, such as "up," "down," "front," "back," "left," "right," "inner," "outer," and "side," are merely for reference to the accompanying drawings and the product's usage state. Therefore, the directional terms used are for illustrating and understanding this invention, and not for limiting it. Additionally, in the accompanying drawings, structures that are similar or identical are indicated by the same reference numerals.

[0028] See Figures 1 to 7 , Figure 1 This is a block diagram of the short-circuit detection circuit provided in the first embodiment of the present invention; Figure 2 This is a block diagram of a short-circuit detection circuit provided in another embodiment of the present invention; Figure 3 This is a circuit diagram of the short-circuit detection circuit provided in the second embodiment of the present invention; Figure 4 This is a circuit diagram of the fast disconnect circuit 32 of the short-circuit detection circuit provided in the third embodiment of the present invention; Figure 5 This is a circuit diagram of the drive push-pull amplifier circuit 20 of the short-circuit detection circuit provided in the fourth embodiment of the present invention; Figure 6 This is a circuit diagram of the blanking capacitor charging circuit 31 of the short-circuit detection circuit provided in the fifth embodiment of the present invention; Figure 7 This is a circuit diagram of the drive fault isolation circuit 33 of the short circuit detection circuit provided in the fifth embodiment of the present invention.

[0029] like Figure 1 As shown, the short-circuit detection circuit includes a control circuit 10, a drive push-pull amplifier circuit 20, and a drive desaturation protection circuit 30. The input terminal of the drive push-pull amplifier circuit 20 is connected to the output terminal of the control circuit 10, and the output terminal of the drive push-pull amplifier circuit 20 is connected to the gate of the IGBT, used to control the IGBT to turn on according to the control signal of the control circuit 10. The drive desaturation protection circuit 30 includes a blanking capacitor charging circuit 31 and a fast disconnect circuit 32. The input terminal of the blanking capacitor charging circuit 31 is connected to the collector of the IGBT, and the output terminal of the blanking capacitor charging circuit 31 is connected to the input terminal of the fast disconnect circuit 32. The input terminal of the fast disconnect circuit 32 is also connected to the output terminal of the control circuit 10 and the input terminal of the drive push-pull amplifier circuit 20, respectively. When the IGBT is short-circuited, the output voltage of the blanking capacitor charging circuit 31 reaches the turn-on voltage of the fast disconnect circuit 32, and the fast disconnect circuit 32 pulls down the input voltage of the drive push-pull amplifier circuit 20 to quickly disconnect the IGBT.

[0030] Specifically, the control circuit 10 may include a control chip U2 for sending control signals, which may be PWM signals. The drive desaturation protection circuit 30 includes a blanking capacitor charging circuit 31 and a fast disconnect circuit 32. The control circuit 10 is connected to the input terminals of the fast disconnect circuit 32 and the drive push-pull amplifier circuit 20, respectively. The control signals output by the control circuit 10 are output to the drive push-pull amplifier circuit 20 and the fast disconnect circuit 32, respectively. The drive push-pull amplifier circuit 20 outputs the control signals to the IGBT, turning on the IGBT.

[0031] When the IGBT is short-circuited, the IGBT exhibits desaturation, meaning it operates in the linear region. At this time, the IGBT's Vce voltage rapidly increases from the saturation voltage drop (around 2V) to around the bus voltage, increasing the input voltage of the blanking capacitor charging circuit 31. This, in turn, increases the output voltage, causing the fast disconnect circuit 32 to conduct, pulling down the input voltage of the drive push-pull amplifier circuit 20, and causing the IGBT to disconnect quickly.

[0032] See Figure 2 As a further embodiment, a drive fault isolation circuit 33 is also included. The input terminal of the drive fault isolation circuit 33 is connected to the output terminal of the blanking capacitor charging circuit 31, and the output terminal of the drive fault isolation circuit 33 is connected to the input terminal of the control circuit 10. When the IGBT is working normally, the drive fault isolation circuit 33 outputs a first signal to the control circuit 10 to make the control circuit 10 continuously output the control signal. When the IGBT is short-circuited, the drive fault isolation circuit 33 outputs a second signal to the control circuit 10 to make the control circuit 10 stop outputting the control signal.

[0033] The output of the drive fault isolation circuit 33 is connected to the input of the control circuit 10, and is used to continuously output a first signal. When the drive fault isolation circuit 33 is not connected to the blanking capacitor charging circuit 31, the drive fault isolation circuit 33 can continuously output the first signal, and the control circuit 10 can continuously output a control signal upon receiving the first signal. When the IGBT is in normal working condition, the voltage output by the blanking capacitor charging circuit 31 does not reach the connection voltage with the drive fault isolation circuit 33, and the blanking capacitor charging circuit 31 and the drive fault isolation circuit 33 are not connected. When the IGBT is short-circuited, the Vce voltage of the IGBT rises to the bus voltage, causing the voltage of the blanking capacitor charging circuit 31 to increase, thereby connecting the blanking capacitor charging circuit 31 and the drive fault isolation circuit 33. The drive fault isolation circuit 33 outputs a second signal to the control circuit 10. Upon receiving the second signal, the control circuit 10 determines that the IGBT is short-circuited and stops outputting the control signal. The first signal can be a high-level signal, and the second signal can be a low-level signal.

[0034] See Figure 3 and Figure 4As a further embodiment, the fast disconnect circuit 32 includes a first transistor Q1, a second transistor Q2, and a third transistor Q3; the base of the first transistor Q1 is connected to the output terminal of the control circuit 10, the collector of the first transistor Q1 and the base of the second transistor Q2 are both connected to the first power supply VCC1, the collector of the second transistor Q2 and the base of the third transistor Q3 are both connected to the output terminal of the blanking capacitor charging circuit 31, the collector of the third transistor Q3 is connected to the input terminal of the drive push-pull amplifier circuit 20, and the emitters of the first transistor Q1, the second transistor Q2, and the third transistor Q3 are all grounded.

[0035] Furthermore, the fast disconnect circuit 32 also includes a first resistor R1, one end of which is connected to the first power supply VCC1, and the other end of which is connected to the collector of the first transistor Q1 and the base of the second transistor Q2.

[0036] Among them, such as Figure 3 As shown, the fast disconnect circuit 32 may include a first transistor Q1, a second transistor Q2, and a third transistor Q3. The collector of the third transistor Q3 is connected to the input terminal of the drive push-pull amplifier circuit 20, which is also connected to the output terminal of the control circuit 10. When the IGBT fails, the voltage output by the blanking capacitor charging circuit 31 reaches the turn-on voltage of the third transistor Q3, turning it on. This allows the input voltage of the drive push-pull amplifier circuit 20 to be rapidly reduced through the ground terminal GND2, thereby disconnecting the IGBT. When the IGBT is operating normally, if the control circuit 10 outputs a low-level signal, the first transistor Q1 is turned off, and the second transistor Q2 is turned on. This allows the output voltage of the blanking capacitor charging circuit 31 to be output to the ground terminal GND2 through the second transistor Q2, reducing the output voltage of the blanking capacitor charging circuit 31 and preventing the blanking capacitor charging circuit 31 from connecting to the drive fault isolation circuit 33, thus preventing false triggering.

[0037] See Figure 3 and Figure 5 As a further embodiment, the drive push-pull amplifier circuit 20 includes a fourth transistor Q4 and a fifth transistor Q5; the base of the fourth transistor Q4 and the base of the fifth transistor Q5 are both connected to the output terminal of the control circuit 10, the collector of the fourth transistor Q4 is connected to the first power supply VCC1, the emitter of the fourth transistor Q4 and the emitter of the fifth transistor Q5 are both connected to the gate of the IGBT, and the collector of the fifth transistor Q5 is grounded.

[0038] Furthermore, the drive push-pull amplifier circuit 20 also includes a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, and a first diode D1; one end of the second resistor R2 is connected to the output terminal of the control circuit 10, and the other end of the second resistor R2 is connected to the base of the fourth transistor Q4 and the base of the fifth transistor Q5, respectively; one end of the third resistor R3 is connected to the emitter of the fourth transistor Q4, and one end of the fourth resistor R4 is connected to one end of the fifth transistor Q5; the other ends of the third resistor R3, the other ends of the fourth resistor R4, and the anode of the first diode D1 are all connected to the gate of the IGBT; the cathode of the first diode D1 and one end of the first capacitor C1 are both connected to the first power supply VCC1; and the other end of the first capacitor C1 is grounded.

[0039] When the IGBT is functioning normally, the control circuit 10 outputs a control signal, such as a high-level signal. This turns on both transistors Q4 and Q5, pulling the IGBT's gate voltage up to its turn-on voltage (typically around 15V), thus turning the IGBT on. When the IGBT is on, it operates in the saturation region, and its voltage drop is the saturation voltage drop. At this time, the IGBT's Vce charges the blanking capacitor charging circuit 31. Since Vce is typically around 2V at this time, the output voltage of the blanking capacitor charging circuit 31 will not be too high, and the blanking capacitor charging circuit 31 is not connected to the drive fault isolation circuit 33.

[0040] See Figure 3 and Figure 6 As a further embodiment, the blanking capacitor charging circuit 31 includes a series circuit composed of multiple blanking resistors connected in series and a second capacitor C2; the input terminal of the series circuit is connected to the collector of the IGBT, the output terminal of the series circuit is connected to one end of the second capacitor C2, the input terminal of the drive fault isolation circuit 33 and the input terminal of the fast disconnect circuit 32 respectively, and the other end of the second capacitor C2 is grounded.

[0041] Furthermore, the blanking capacitor charging circuit 31 also includes a second diode D2, the positive terminal of the second diode D2 is connected to the output terminal of the series circuit, and the output terminal of the second diode D2 is connected to the first power supply VCC1.

[0042] The blanking capacitor charging circuit 31 includes multiple blanking resistors, such as... Figure 5 As shown, Figure 5Resistors RC1, RC2, ..., and RCN are all blanking resistors. During normal IGBT operation, the IGBT's Vce charges the second capacitor C2 through the blanking resistors. The capacitance of the second capacitor C2 is approximately 100pF. The number of blanking resistors is determined by the bus voltage, ensuring that when Vce is equal to the bus voltage, the current flowing through the blanking resistors is approximately 1mA. When the IGBT is short-circuited, the Vce voltage rises to the bus voltage, and the voltage of the second capacitor C2 gradually reaches the connection voltage with the drive fault isolation circuit 33. The blanking capacitor charging circuit 31 then connects to the drive fault isolation circuit 33.

[0043] See Figure 3 and Figure 7 As a further embodiment, the drive fault isolation circuit 33 includes a third diode D3 and an optocoupler U1; the negative terminal of the third diode D3 is connected to the output terminal of the blanking capacitor charging circuit 31, the positive terminal of the third diode D3 is connected to one end of the optocoupler U1, and the other end of the optocoupler U1 is connected to the input terminal of the control circuit 10.

[0044] Furthermore, the drive fault isolation circuit 33 also includes a fifth resistor R5 and a sixth resistor R6; one end of the fifth resistor R5 is connected to the second power supply VCC2, the other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, one end of the sixth resistor R6 is also connected to the optocoupler U1, and the other end of the sixth resistor R6 is connected to the input terminal of the control circuit 10.

[0045] Specifically, when the output voltage of the blanking capacitor charging circuit 31 does not reach the breakdown voltage of the third diode D3, the third diode D3 is not conducting, and the fault isolation circuit 33 and the blanking capacitor charging circuit 31 are not conducting. When the output voltage of the blanking capacitor charging circuit 31 reaches the breakdown voltage of the third diode D3, the third diode D3 conducts, and the fault isolation circuit 33 and the blanking capacitor charging circuit 31 are connected, so that the optocoupler U1 is conducting, thereby pulling down the output signal and then outputting the second signal.

[0046] As a further embodiment, the control circuit 10 includes a control chip U2 and an isolator U3; the input terminal of the control chip U2 is connected to the output terminal of the drive fault isolation circuit 33, the output terminal of the control chip U2 is connected to the input terminal of the isolator U3, and the output terminal of the isolator U3 is connected to the input terminals of the fast disconnect circuit 32 and the drive push-pull amplifier circuit 20, respectively.

[0047] The control circuit 10 includes a control chip U2 and an isolator U3. The control chip U2 can be a DSP chip, and the isolator U3 is a commonly used isolator U3 in the art. The control chip U2 is used to output a control signal to drive the push-pull amplifier circuit 20 and the fast disconnect circuit 32 according to the first signal, and to stop outputting the control signal according to the second signal.

[0048] The short-circuit detection circuit disclosed in this invention can quickly disconnect the IGBT by rapidly reducing the input voltage of the drive push-pull amplifier circuit through a fast disconnect circuit when a short circuit occurs. At the same time, it can also ensure that the control circuit stops outputting control signals through a drive fault isolation circuit. Thus, short-circuit protection of the IGBT can be achieved without installing a dedicated driver chip, reducing cost and maintenance difficulty.

[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A short-circuit detection circuit, characterized in that, include: Control circuit; A push-pull amplifier circuit is provided, wherein the input terminal of the push-pull amplifier circuit is connected to the output terminal of the control circuit, and the output terminal of the push-pull amplifier circuit is connected to the gate of the IGBT, and is used to control the IGBT to conduct according to the control signal of the control circuit. The drive desaturation protection circuit includes a blanking capacitor charging circuit and a fast disconnect circuit. The input terminal of the blanking capacitor charging circuit is connected to the collector of the IGBT, and the output terminal of the blanking capacitor charging circuit is connected to the input terminal of the fast disconnect circuit. The input terminal of the fast disconnect circuit is also connected to the output terminal of the control circuit and the input terminal of the drive push-pull amplifier circuit. When the IGBT is short-circuited, the output voltage of the blanking capacitor charging circuit reaches the conduction voltage of the fast disconnect circuit, and the fast disconnect circuit pulls down the input voltage of the input terminal of the drive push-pull amplifier circuit to make the IGBT disconnect quickly. The fast disconnect circuit includes a first transistor, a second transistor, and a third transistor. The base of the first transistor is connected to the output of the control circuit. The collector of the first transistor and the base of the second transistor are both connected to a first power supply. The collector of the second transistor and the base of the third transistor are both connected to the output of the blanking capacitor charging circuit. The collector of the third transistor is connected to the input of the drive push-pull amplifier circuit. The emitters of the first transistor, the second transistor, and the third transistor are all grounded. The fast disconnect circuit also includes a first resistor, one end of which is connected to the first power supply, and the other end of which is connected to the collector of the first transistor and the base of the second transistor.

2. The short-circuit detection circuit as described in claim 1, characterized in that, It also includes a drive fault isolation circuit, the input of which is connected to the output of the blanking capacitor charging circuit, and the output of which is connected to the input of the control circuit. When the IGBT is working normally, the drive fault isolation circuit outputs a first signal to the control circuit so that the control circuit continuously outputs the control signal. When the IGBT is short-circuited, the drive fault isolation circuit outputs a second signal to the control circuit so that the control circuit stops outputting the control signal.

3. The short-circuit detection circuit as described in claim 1, characterized in that, The drive push-pull amplifier circuit includes a fourth transistor and a fifth transistor; The bases of the fourth transistor and the fifth transistor are both connected to the output of the control circuit. The collector of the fourth transistor is connected to the first power supply. The emitters of the fourth transistor and the fifth transistor are both connected to the gate of the IGBT. The collector of the fifth transistor is grounded.

4. The short-circuit detection circuit as described in claim 3, characterized in that, The drive push-pull amplifier circuit also includes a second resistor, a third resistor, a fourth resistor, a first capacitor, and a first diode; One end of the second resistor is connected to the output terminal of the control circuit, and the other end of the second resistor is connected to the base of the fourth transistor and the base of the fifth transistor, respectively. One end of the third resistor is connected to the emitter of the fourth transistor, and one end of the fourth resistor is connected to one end of the fifth transistor. The other ends of the third resistor, the other ends of the fourth resistor, and the anode of the first diode are all connected to the gate of the IGBT. The cathode of the first diode and one end of the first capacitor are both connected to the first power supply, and the other end of the first capacitor is grounded.

5. The short-circuit detection circuit as described in claim 2, characterized in that, The blanking capacitor charging circuit includes a series circuit consisting of multiple blanking resistors connected in series and a second capacitor. The input terminal of the series circuit is connected to the collector of the IGBT, and the output terminal of the series circuit is connected to one end of the second capacitor, the input terminal of the drive fault isolation circuit, and the input terminal of the fast disconnect circuit, respectively. The other end of the second capacitor is grounded.

6. The short-circuit detection circuit as described in claim 5, characterized in that, The blanking capacitor charging circuit also includes a second diode, the anode of which is connected to the output terminal of the series circuit, and the output terminal of which is connected to the first power supply.

7. The short-circuit detection circuit as described in claim 2, characterized in that, The drive fault isolation circuit includes a third diode and an optocoupler. The negative terminal of the third diode is connected to the output terminal of the blanking capacitor charging circuit, the positive terminal of the third diode is connected to one end of the optocoupler, and the other end of the optocoupler is connected to the input terminal of the control circuit.

8. The short-circuit detection circuit as described in claim 7, characterized in that, The drive fault isolation circuit also includes a fifth resistor and a sixth resistor; One end of the fifth resistor is connected to the second power supply, the other end of the fifth resistor is connected to one end of the sixth resistor, one end of the sixth resistor is also connected to the optocoupler, and the other end of the sixth resistor is connected to the input terminal of the control circuit.

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